The present invention relates generally to a coating. More particularly, the present invention relates to a coating suitable for use as a wear-resistant coating for a gas turbine engine component.
A gas turbine engine component, such as a seal plate in a rotary seal mechanism, is often subject to high friction and high temperature operating conditions. After some time in service, the friction typically causes the surface of the component that is exposed to the friction to wear. The wear is generally undesirable, but may be especially undesirable and problematic for a seal mechanism that acts to segregate two or more different compartments of the gas turbine engine. For example, if a sealing component wears (or erodes) and is no longer effective, fluid from one compartment may leak into another compartment. In some portions of a gas turbine engine, failure of the seal mechanism is detrimental to the operation of the gas turbine engine. In those cases, the gas turbine engine may need to be removed from service and repaired or replaced if a part of the seal mechanism wears to the point of seal failure.
A rotary seal mechanism separates two compartments of the gas turbine engine. A rotary seal mechanism typically includes a first component formed of a hard material, such as a carbon seal, that at least in part contacts a surface of a second component formed of a softer material, such as a seal plate, in order to segregate two or more compartments of the gas turbine engine. In some applications, the seal plate rotates as the carbon seal remains fixed, while in other applications, the carbon seal rotates as the seal plate remains fixed. As the seal plate and carbon seal contact one another, the operating temperature and friction levels of both components increase. This may cause the seal plate, which is formed of a softer material than the carbon seal, to wear and deteriorate. The relative vibration between the seal plate and the carbon seal during the gas turbine engine operation may also cause frictional degradation and erosion of the seal plate.
It is important to minimize the wear of the seal plate in order to help prevent the rotary seal mechanism from failing. In order to mitigate the wear and deterioration of the seal plate and extend the life of the seal plate, a wear-resistant coating may be applied to at least one of the contacting surfaces (i.e., the surface of the seal plate that contacts the carbon seal). However, it has been found that many existing wear-resistant coatings crack and spall under the increasingly high engine speeds and pressures. Therefore, it would be desirable to have improved wear-resistant coatings.